ZFS regimen: scrub, scrub, scrub and scrub again.

[Adam Nowacki]

On 2013-01-24 15:45, Zaphod Beeblebrox wrote:
> Ok... so my question then would be... what of the small files.  If I write
> several small files at once, does the transaction use a record, or does
> each file need to use a record?  Additionally, if small files use
> sub-records, when you delete that file, does the sub-record get moved or
> just wasted (until the record is completely free)?

Each file is a fully self-contained object (together with full parity) 
all the way to the physical storage. A 1 byte file on RAID-Z2 pool will 
always use 3 disks, 3 sectors total for data alone. You can use du to 
verify - it reports physical size together with parity. Metadata like 
directory entry or file attributes is stored separately and shared with 
other files. For small files there may be a lot of "wasted" space.